Composting apparatus with comminution, moisture control, and mascerator means

Abstract

A system for composting solid waste material wherein in initial treatment stages an optimum particle size is developed at a comminution station following which through an initial air classification arrangement, heavy inorganic materials are segregated to the extent that aluminum, glass and paper characterized products are removed for recycling purposes. A characterizing feature of the invention resides in the development of an optimized moisture content or digestible classified size optimized material at a relatively early stage prior to maceration developing a pulpous substance for digestion. A pug-mill arrangement is utilized for adding optimized moisture prior to digestion and maceration and a cage-mill is utilized for the maceration stage of the process.

I claim: 
     
       1. A system for treating solid waste by composting the organic material thereof, comprising: receiving station means for receiving untreated waste material;   input transfer means for moving said untreated waste material from said receiving station means at a select transfer rate;   comminution means for comminuting said waste material to derive a size limited material having a select maximum average particle size;   feedback means from said comminution means to adjust the select transfer rate to avoid overloading said comminuting means;   means for mixing said size limited material with water moisture, by the substantially non-destructive agitation thereof over an interval of time selected to derive a substantially uniform moisture content for said size limited material in the range of about 50-60% by weight;   macerator means for converting said size limited material of select moisture content into a material of pulp-characterized consistency said conversion being carried out without the substantial further addition of water and said material of pulp-characterized consistency having a moisture content remaining moisture optimized for said aerobic digestion; and   digester means for inducing the aerobic decomposition of said material of pulp-characterized consistency.   
     
     
       2. The system for treating solid waste of claim 1 including means for introducing said water moisture to said mixing means as a water-born sludge. 
     
     
       3. The system of claim 1 in which said mixing means comprises a pug mill. 
     
     
       4. The system of claim 1 in which said comminution means is configured to derive a said size limited material having a maximum average particle size exhibiting an equivalent diameter of about 6 inches. 
     
     
       5. The system of claim 1 in which said macerator means comprises a cage mill. 
     
     
       6. The system of claim 1 including means for transferring said material of pulp-characterized consistency substantially directly to said digester means. 
     
     
       7. The system of claim 1 further comprising separation means configured to receive said size limited material from said comminution means and including a magnetically actuated stage for removing ferrous metal material therefrom and air classification means including a stage for removing heavy inorganic characterized materials therefrom and a stage for removing plastic-characterized materials therefrom. 
     
     
       8. The system of claim 7 in which: said air classification means includes means for wetting said size limited material to an extent equal to or less than that amount of moisture required to provide said uniform select moisture content; and   said separation means includes an aspirator stage configured and arranged to remove paper characterized materials from said size limited material.   
     
     
       9. The system of claim 1 in which: said receiving station means is configured and arranged for temporarily retaining said untreated waste material within a substantially enclosed environment of atmospheric air;   said digester means is configured for inducing said aerobic decomposition at least in part by means forcibly transferring oxygen laden air through said material of pulp-characterized consistency; and   including means for transferring said atmospheric air from said enclosed environment to said digester means air transfer means.   
     
     
       10. A system for treating solid waste by composting the organic material thereof, comprising: receiving station means for receiving untreated waste material;   input transfer means for moving said untreated waste material from said receiving station means at a select transfer rate;   comminution means for comminuting said waste material to derive a size limited material having a select maximum average particle size;   feedback means from said comminution means to adjust the select transfer rate to avoid overloading said comminuting means;   at least one pug mill for mixing said size limited material with water moisture, the quantity of said water moisture being selected to derive a substantially uniform moisture content for said size limited material within a range selected for enhancing aerobic digestion;   at least one cage mill configured for receiving said size limited material of select moisture content and converting it into a material of pulp-characterized consistency; and   digester means for inducing the aerobic decomposition of said material of pulp-characterized consistency.   
     
     
       11. The system of claim 10 in which said pug mill is configured for deriving a said moisture content uniformly dispersed within said size limited material and within a range of about 50-60% by weight. 
     
     
       12. The system of claim 10 including means for introducing at least a portion of said water moisture to said pug mill as a water-born sludge. 
     
     
       13. The system of claim 10 in which said comminution means if configured to derive a said size limited material having a maximum average particle size exhibiting an equivalent diameter of about 6 inches. 
     
     
       14. The system of claim 13 further comprising separation means configured to receive said size limited material from said comminution means and including a magnetically actuated stage for removing ferrous metal material therefrom and air classification means including a stage for removing heavy inorganic characterized materials therefrom and a stage for removing plastic-characterized materials therefrom. 
     
     
       15. The system of claim 14 in which: said receiving station means is configured and arranged for temporarily retaining said untreated waste material within a substantially enclosed environment of atmospheric air;   said digester means is configured for inducing said aerobic decomposition at least in part by means forcibly transfering oxygen laden air through said material of pulp-characterized consistency; and   including means for transferring said atmospheric air from said enclosed environment to said digester means air transfer means.   
     
     
       16. The system of claim 15 including means for transferring said material of pulp-characterized consistency substantially directly to said digester means. 
     
     
       17. The system of claim 15 in which: said air classification means includes means for wetting said size limited material to an extent equal to or less than that amount of moisture required to provide said uniform select moisture content; and   said separation means includes an aspirator stage configured and arranged to remove paper characterized materials from said size limited material.